The overall goals of this K99/R00 grant application are to transition to an independent investigator position and to identify and characterize the early events in inv(16) associated acute myeloid leukemia (AML). My long-term goal is to establish myself as an independent investigator in the field of myeloid leukemia, with a focus on inv(16) associated AML. Inv(16) creates a fusion gene between the transcription factor CBFB, and the gene encoding smooth muscle myosin heavy chain, MYH11. The resulting fusion gene, CBFB-MYH11 encodes the protein CBF2- SMMHC. Based on my previous research, I hypothesize that expression of CBFB-MYH11 induces an abnormal population of leukemia initiating cells (LIC) through distinct changes in gene expression. Understanding the mechanism that generates these LICs may provide new drug targets for the treatment of inv(16) AML. Thus, I propose to (Specific Aim 1) characterize and isolate the Cbfb-MYH11+ leukemia initiating population; (Specific Aim 2) use bioinformatic approaches to analyze Cbfb-MYH11 induced changes in gene expression. Completing these Specific Aims will provide: (i) an improved understanding of CBFB-MYH11 LICs, (ii) potential mechanisms of CBFB-MYH11 induced leukemogenesis, (iii) training in computational methods for analysis of gene expression data and genome wide sequencing data.